The present invention generally relates to a driving mechanism and a friction mechanism of a camera which independently drives plural loads with respect to a specified operation such as an aperture, a mirror, or a shutter cocking operation.
Conventionally, there has been proposed various kinds of operating mechanisms for driving plural loads by a single motor. In such mechanisms, the increase of the number of the loads has resulted in difficulty to selectively transmit the outputted power from the motor to each load. Therefore, as well as the selection has been carried out by using the power outputted from the motor, a specified amount of load set at a specified value has been sequentially carried out, plural loads have been driven by using a mechanism having one input portion and two output portions such as a differential gear mechanism, or a selection mechanism has been selected by other actuator or a manual operation from the outside of the mechanism.
In these mechanisms, in order to carry out plural loads by a single motor, the operation area of the loads is limited, a complex distributing mechanism with many limitation is required, an outside switching means is required. Then, such mechanism has a lot of disadvantages such as a complex, a heavier and a large size in the construction, a limited operation area, a higher manufacturing cost, and a higher failure rate. Hereinbelow, the disadvantages will be explained more concretely.
FIG. 29 shows a mechanism according to a first conventional example. In FIG. 29, reference M denotes a motor, R a specified reduction transmitting mechanism, and A a first load, B1, B2, and B3 a second load, a third load, and a fourth load, respectively. In this construction, the first load A is driven through the reduction transmitting mechanism R by the rotational power of the motor M. Then, after the second load B1, the third load B2, and the fourth load B3 are simultaneously driven thereby, the first load is driven again.
In the mechanism, the loads A, B1, B2, and B3 are generally driven within the respective limited operation area, after the load in the specified section has been driven, the load in the next section is driven. Therefore, there have been problems that operation amounts, operating directions, and operation orders of the loads are limited. In order to drive the plural loads by the mechanism, the number of the section is required to increase, so that the limitation further increases disadvantageously.
FIG. 30 shows a mechanism according to a second conventional example. In FIG. 30, reference M denotes a reversible motor, R a specified reduction transmitting mechanism, X and Y one-way clutches for respectively transmitting the power of the motor in only one direction in which are different with each other, and A1, A2, A3, B1, and B2 a first, a second, a third, a fourth, and a fifth load, respectively.
In the mechanism, when the motor M is driven for rotation in one direction, the rotational power of the motor is transmitted through the mechanism R and the clutch X to a load system A including the loads A1, A2, and A3, so that the first load A1, the second load A2, the third load A3, the first load A1 . . . are sequentially driven in order. Then, when the motor M is driven for rotation in the other direction, the rotational power of the motor is transmitted through the mechanism R and the clutch Y to the load B1 or the loads B1 and B2 to drive the load B1 or the loads B1 and B2 to rotate in a specified direction. In the construction of the mechanism, since the load system A and a load system B including the loads B1 and B2 connect with the motor M through the clutches X and Y, the system A and the system B are changeable only by reversing the rotational direction of the motor without the limitation with respect to the order between the systems A and B and the operation amount of the loads.
However, in the mechanism, since both of the one and the other directions of the motor are used to drive the loads and the number of the rotational direction of the motor can not be increased, the number of the load system also can not be increased. Each load is driven in only one direction and can not be driven in the other direction.
FIG. 31 shows a mechanism according to a third conventional example. In FIG. 31, reference M denotes a reversible motor, R a reduction transmitting mechanism, D and G differential gears having one input portion and two output portions, A1, A2, and A3 a first load system A driven by a first outputted power of the differential gears D and G, B1 and B2 a second load system B driven by a second outputted power of the differential gears D and G, X a one-way clutch for transmitting the rotational power of the motor M to drive for rotation in only one direction, C a third load system driven through the clutch X, and P a switching signal for switching an output system of the differential gears D and G as required.
The mechanism has an advantage that both of the systems A and B can be driven by a driving force in one direction of the motor i.e. without reversing the rotational direction of the motor M and can be driven in a reverse direction only by rotating the motor reversely as compared with the second conventional example. The third load system C can be driven by the rotation of the motor M in the operational direction of the clutch X. In this case, the load system A or B is driven reversing.
However, in the construction of the mechanism, since in order to properly use the systems A and B, the signal P is required, the construction becomes complex and it is generally difficult to output the signal P from the systems A and B and it is required to execute the operation for returning the system to the original state after switching.
Furthermore, there has been proposed cameras for completely separating a film take up spool from a reduction gears mechanism connected with a motor in non-winding of a film. In such cameras, if no load applies to the spool for winding a film therearound, the spool conversely rotates by a bias force caused by the fact that the film wound around the spool intends to loose to loose the film, so that the film frame for phototaking is shifted from a specified position. In order to prevent such a problem, friction mechanisms for applying a friction torque to the spool have been proposed.
As one of the friction mechanisms, there have been mechanisms with various constructions. For example, as shown in FIG. 32, in a camera which the outer cylinder of a motor 181 is employed as the spool 181b, a friction mechanism is disposed on the upper of the spool 181b. The mechanism is generally so constructed that a spool gear 182 is relatively rotatably disposed on the upper surface of the spool 181b, a spool gear driving gear 183 is connected with the spool gear 182, and a spring 184 for spool friction is wound around the outer surface of the spool gear 182 while engaging one end of the spring 184 with the spool 181b. In the construction, the spool gear 182 is driven for rotation by the driving gear 183 to rotate the spool 181b through the spring 184, and only when the spool 181b is driven for rotation by a force over a specified value, the spool 181b can rotate with respect to the spool gear 182. Therefore, the film around the spool 181b is prevented from loosening by only applying a torque over the force for loosing the film to the spool 181b so as to become simple in construction. However, it is disadvantageously required to hold to prevent the rotation of the spool gear 182 in nonwinding of the film, and thus the mechanism becomes complex in construction.
However, in order to apply to the spool 181b itself the torque over the force for loosing the film, the friction mechanism must be located on the upper of the motor 181. The reason is that the driving shaft of the motor is protruded at the lower of the motor 181 to dispose a winding unit, i.e., a winding drive mechanism and if the friction mechanism is disposed at the lower thereof, the construction becomes complex. Then, a camera having a flexible circuit substrate and a liquid crystal display at the upper of the motor has the following disadvantages. That is, the arrangement of the friction mechanism on the upper portion causes the increase in height of the camera and results in limitation in the arrangement of the camera design. Furthermore, it is required to assemble the friction mechanism into the spool from the upper side of the motor after assembling the motor thereinto from the lower side of the camera, resulting in increasing the assembly manday thereof. It is also required to adjust the friction force after assembly because the friction mechanism is not constructed as a unit which is preadjustable before assembly and which is not required to adjust it after assembly.
Moreover, conventionally, there have been electric film rewinding apparatuses with various constructions. As one example of the apparatuses, there has been an apparatus in which a wound film is rewound into a film cartridge by using the rotational driving power of an electrical motor. The apparatus has a planetary gear mechanism in which a planetary gear rotates around a sun gear. In the apparatus, the planetary gear engages with or disengages from a film rewinding gear, serving as a driven gear, while rotating around the sun gear, and thereby the winding operation is changed into the rewinding operation. In this case, the planetary gear can not rotate in the sequential process to causes the trouble unless the planetary gear certainly disengages from the rewinding gear after completion of rewinding operation. Such a problem that the planetary gear can not rotate around the sun gear often arises in the case where the wound film intends to loose in the cartridge after the completion of the film rewinding operation so as to conversely rotate the rewinding gear through a rewinding folk and thus the planetary gear tightly engages with the rewinding gear.
As one of such an apparatus, there has been proposed a mechanism for certainly executing the operation for disengaging the planetary gear from the rewinding gear, as disclosed, for example, in Japanese Laid-open Utility Model Publication No. 55-42822. This apparatus is so constructed that the planetary gear rotates around a sun gear to engage with the rewinding gear in rewinding the film but can not rotate therearound to disengage therefrom. Therefore, in the apparatus, a special releasing member is arranged to forcedly disengage the planetary gear from the rewinding gear while interlocking opening and closing the back lid of the camera. Further, the engagement between a rewinding folk and the shaft of a cartridge is released while interlocking the operation of the releasing member for releasing the engagement between the planetary gear and the rewinding gear.
As stated the above, in the apparatus with the above construction, the releasing member interlocking the lid allows the planetary gear to rotate around the sun gear in a direction in which the engagement between the planetary gear and the rewinding gear is released. That is, the direction in which the planetary gear can rotate around the sun gear by the driving force of a motor driving system which is transmitted from a series of gears train is only the direction in which the planetary gear engages with the rewinding gear. Then, the planetary gear can not rotate in the reverse direction by the driving force thereof. Therefore, it is required to provide with a releasing member which allows the planetary gear to rotate in the reverse direction in which the planetary gear disengages from the rewinding gear at a desirable timing while interlocking the operation of the back lid of the camera. In other words, the mechanism can not return to the original condition by itself. Thus, since the additional driving means different from a driving means in the motor driving system, that is, a manual operation for releasing the engagement between the planetary gear and the rewinding gear, is required. If the releasing operation is executed at an undesirable timing, it is possible to cause a trouble. If another safety mechanism for preventing such a trouble is provided, the number of the parts in the mechanism further increases and the size of the construction thereof becomes bigger.
Furthermore, since the force for releasing the engagement is a bias force of a spring, it is difficult to set the bias force thereof to a specified value. When the planetary gear tightly engages with the rewinding gear not to rotate around the sun gear in the direction for releasing, some amount of the force for releasing is required to be applied to the releasing member, so that in the case where the mechanism of the disengagement interlocks the operation of the back lid of the camera, a larger force is required to close the lid and thus it becomes difficult to close it.
Moreover, there has been proposed a driving control apparatus of a camera which controls to drive a mechanism cocking system and a film winding system by a single motor. The apparatus is so constructed that a mechanism cocking operation and a film winding operation are always executed according to the drive of the motor. Then, for example, in a case where an initial film transporting operation for transporting a film to reach first frame thereof without exposure, i.e., the so-called initial loading operation, is executed when a film is loaded in the camera body, the mechanism cocking operation and the film winding operation are alternatively executed as a series of operations without a shutter releasing operation. Therefore, it causes a problem that the period of time required to execute the initial loading operation is larger than the period of time required to only wind the film. In such a camera with the single motor, film winding operation is executed uselessly when the release operation is executed in unloading the film. Then, conventionally, it has been proposed to provide a special motor for winding the film and a motor for executing the mechanism cocking operation, and thus, for example, the release operation can be executed by stop of the motor for the film winding operation without the film winding operation in unloading the film. Then, the operation to be executed originally can be done without unnecessary operation.
In a case where in order to miniaturize the size of the camera, it is required to execute a release, a mechanism cocking, a film winding, and a film rewinding operation by a single motor. Then, as well as the normal release operation, when only the release and the mechanism cocking operations are required in such a case as the release operation and the initial loading operation are executed in unloading the film, or when the film winding operation or the film rewinding operation is required only, the drive of the motor without unnecessary operation for the sake of energy saving and quick operation.